1. Field of the Invention
The present invention relates to a storage medium having a game program stored thereon and a game apparatus, and more specifically to a storage medium having a game program stored thereon and a game apparatus which use an input device connected to the game apparatus main body via wireless communication.
2. Description of the Background Art
Conventionally, game apparatuses using an input device connected to a game apparatus main body via wireless communication have been developed as described in, for example, “Nintendo Game Cube Wireless Controller WaveBird User's Manual” (Nintendo Co., Ltd., Dec. 5, 2002 (hereinafter, referred to as non-patent document 1).
The input device described in non-patent document 1 is connected to a game apparatus main body via wireless communication. In general, an input device connected to a game apparatus main body via wireless communication, such as the input device described in non-patent document 1, cannot be supplied with power from the game apparatus main body. Therefore, such an input device has a built-in dry battery or a rechargeable battery. However, the power supply such as a dry battery or a rechargeable battery has a limited life. When the life has expired, i.e., the battery is dead, the built-in dry battery needs to be replaced with a new dry battery or the rechargeable battery needs to be recharged. The input device described in non-patent document 1 notifies a player that the dry battery needs to be replaced as follows. When the player turns the power switch on, the power lamp provided in the input device is lit up. As the dry battery is consumed, the power lamp gradually becomes dark. The input device urges the player to replace the dry battery with a new one while the battery still has a certain remaining amount therein.
However, the player playing a game with the game apparatus does not often visually check the input device held in his/her hand, and plays while watching the game image displayed on a display device. Although using the input device described in non-patent document 1, the player may continue playing without noticing that the power lamp is becoming gradually dark. Therefore, it often occurs that the player notices that the battery needs to be replaced only after the battery is dead and the game operation cannot be performed because there is no wireless communication between the game apparatus main body and the input device. When the player notices that the battery is dead, the wireless communication with the game apparatus main body cannot be satisfactorily performed any more. Therefore, the input device cannot, for example, instruct the game apparatus main body to stop the game. As a result, the play proceeds against the intention of the player until the player completes replacing or recharging the battery.